18049261 has 2 divisors, whose sum is σ = 18049262. Its totient is φ = 18049260.

The previous prime is 18049247. The next prime is 18049267. The reversal of 18049261 is 16294081.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17682025 + 367236 = 4205^2 + 606^2 .

It is an emirp because it is prime and its reverse (16294081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18049261 - 2²¹ = 15952109 is a prime.

It is a super-2 number, since 2×18049261² = 651551645292242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18049267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9024630 + 9024631.

It is an arithmetic number, because the mean of its divisors is an integer number (9024631).

Almost surely, 2^18049261 is an apocalyptic number.

It is an amenable number.

18049261 is a deficient number, since it is larger than the sum of its proper divisors (1).

18049261 is an equidigital number, since it uses as much as digits as its factorization.

18049261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 18049261 is about 4248.4421850838. The cubic root of 18049261 is about 262.3129963653.

The spelling of 18049261 in words is "eighteen million, forty-nine thousand, two hundred sixty-one".